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What you should Know about Farmi Winches

TYPES OF WINCHES

The two types of winches that are available are the single drum winch and the double drum winch. The single drum winch totally dominates the market, it is used for winching and skidding worldwide. The double drum winch is used to power high lead systems in Alpine terrain.

WINCH SIZES

Skidding winches are available for farm tractors that range in size from 17 HP to 200 HP. The pulling capacities of the winches range from 6000 lb. to 18.000 lb.. The pulling capacity is measured when the winch drum wraps the cable for the first time on an empty drum. The pulling capacity reflects the weight that the winch can lift clear off the ground. How much weight the winch can actually pull out depends on many factors such as the amount of cable on the drum, the leaning of the terrain and how much the logs dig into the ground when winching. There should be some relation between the pulling capacity and the size of the tractor that the winch is used on. The table below gives some direction for you when you are selecting a winch for your tractor.

FEATURES TO LOOK FOR IN A SKIDDING WINCH

Separate Winch Frame

The winch mechanism should have its own, separate frame which is detachable from the rest of the winch. The separate frame makes it easy to take out the entire winch mechanism for service and repair. Winches where the winch mechanism does not come out in one piece are very difficult to work on.

Enclosed Winch Mechanism

The winch mechanism should be totally covered so the components of the winch are not exposed to water, snow, ice or branches.

Option To Control Winch From Driver's Seat

The controls for the clutch engagement and the brake must be accessible from the operator's seat on the tractor. The operator usually stands on the ground in a safe place 6-8 feet on the side of the winch when winching in a load. The load is then skidded out and it is common that one comes to a wet spot on the skid trail. The operator should be able to drop the load before the wet spot, drive the tractor through the mud and then winch in the load from dry ground on the other side without climbing off and on the tractor. To enable all this to be done from the tractor seat one should choose a winch where the clutch engagement control rope and the drum brake control is accessible from the cab of the tractor. Winches which can be operated from the driver's seat have the clutch control rope in the center on top of the winch. The control rope runs through a swivel pulley which enables operation from any direction.

Clutch Protected From Burnout

The winching process creates a lot of heat in the clutch mechanism. The clutch pads will eventually burn and glaze if the heat is not pulled away from the clutch. Top of the line equipment have heat sinks built into the clutch which will absorb the heat that has been generated. That prevents glazing of the clutch. Those winches can be identified by the 5 year warranty the manufacturer gives to the clutch. If there is no warranty on the clutch and there is warnings against slipping the clutch in the operator's manual, move on.

The Upper Pulley

The winch is pushed toward the ground when the cable is pulled through the upper cable pulley. This down pressure anchors the winch in place when winching. It is therefore advantageous to choose a winch where the upper pulley is higher above the ground because that will increase down pressure and anchorage.The diameter of the upper pulley is also a factor to observe. The cable will wear out faster if the pulley diameter is very small.

The Lower Snatchblock

The cable is run through the lower snatchblock when skidding. This lowers the center of gravity, so larger loads can be winched out. The lower snatchblock also functions as a hinge, so that the tractor turns easier. The snatchblock must be constructed so that the cable is easy to place in it and easy to remove from it. The cable must stay securely in place when skidding. The common method to achieve the above requirements is the design where the cable goes into the snatchblock only when it is turned sharply to the right. The cable stays securely in the snatchblock because the tractor can not turn sharp enough to release the cable.

Height Of The Winch

The upper pulley is usually on the top of the winch, so the needed down pressure for anchorage comes from the height of the winch.Weight Of The Winch The winch must be built to withstand the stresses of logging. The weight of the winch is one indication of durability. Another indication of durability is the design of the winch. Is the design durable because the form of the material provides strength to it? If, for example you are comparing two winch frames. One has a deep frame with many folds the other had a shallow frame with less folds. You should choose the deep frame with the folds. The strength comes from the form.

The Main Frame Of The Winch

The frame should provide a rigid base for the winch mechanism. A blade on the bottom of the frame will dig into the ground and thus anchor the winch and tractor in place. The blade can also be used for stacking the logs in the landing. The frame should have brackets for transporting skidding chains. Some winches even have toolboxes and brackets for transporting a chain saw on the winch.

THE CABLE

The cable that works best in skidding winches is steel core wire rope. There is other types of cable being sold to this use and one should especially avoid "aircraft cable" which is a cheap quality cable too stiff for use in a skidding winch. Aircraft cable has a tendency to retain the form of the winch drum, so after a while it looks like one is pulling out a slinky from the drum.Wire rope of 6X25 type is suitable for use in skidding winches. The wires on the outside should be thicker than the wires on the inside. The thicker outside wires provide longer wear and the thinner inside wires keeps the cable flexible.

THE CABLE CLAMPS

The cable clamps should put equal pressure on both sides of the cable. " Iron Grip" clamps are the most popular. They have a round form so they do not get hooked onto roots and branches. They have 2 bolts which tighten the lock which enables repairs at the work site. Iron Grip cable clamps are very expensive, but you can use them a long time if you replace the bolts when needed.Cables which has been terminated by pressing a metal bushing on the ends can not be repaired in the field, and should therefore be avoided.

Jaakko Sarvela, together with his brother Juhani, invented the three point hitch mounted skidding winch. The inventor is pictured here in October of 2003 with a 41 year old early model of the Farmi Winch.